Threatening wastewater is a global challenge and is of the prime focus and research area in environmental sector. In order to treat wastewater generated by various sources, there has been increased use of Constructed Wetlands (CWs) that holds a promising mechanism for treating wastewater. These engineered systems are designed in a manner which is a nature based solution for purification process of wastewater. CWs present an eco-friendly low energy alternative to conventional waste water treatment plants. CWs utilize different fungi in order to produce an effective output. This chapter discusses about the different types of fungi that are used for wastewater treatment along with the case studies, designing of CWs, cost effectiveness, limitations, uses of fungal bioreactors and way forward. Use of fungi in CWs can the potential to even degrades organic and inorganics pollutants which are not usually treated by conventional wastewater treatment plants. The need of such research paves our way for attaining sustainability and achieve SDG goals.